Creating an Environment

trac-admin will ask you for the name of the project, the
database connection string (explained below), and the type and path to
your source code repository.

Note: The web server user will require file system write permission to
the environment directory and all the files inside. Please remember to set
the appropriate permissions. The same applies to the Subversion repository
Trac is eventually using, although Trac will only require read access as long
as you're not using the BDB file system.

Database Connection Strings

Since version 0.9, Trac supports both SQLite,
PostgreSQL and MySQL as
database backends. The default is to use SQLite, which is probably sufficient
for most projects. The database file is then stored in the environment
directory, and can easily be backed up together with the
rest of the environment.

The connection string for an embedded SQLite database is:

sqlite:db/trac.db

If you want to use PostgreSQL or MySQL instead, you'll have to use a
different connection string. For example, to connect to a PostgreSQL
database on the same machine called trac, that allows access to the
user johndoe with the password letmein, use:

postgres://johndoe:letmein@localhost/trac

If PostgreSQL is running on a non-standard port (for example 9342), use:

postgres://johndoe:letmein@localhost:9342/trac

Note that with PostgreSQL you will have to create the database before running
trac-admin initenv.

And make sure PostgreSQl DB name is "trac". What worked for me:
And didn't work uppercase trac-user-name

(Just to remind you, if you don't have a sudo/su setup, you just need to do the createdb and psql statements. That threw me the first couple of times I read this.)

Source Code Repository

You'll first have to provide the type of your repository (e.g. svn for Subversion,
which is the default), then the path where the repository is located.

If you don't want to use Trac with a source code repository, simply leave the path empty
(the type information doesn't matter, then).

For some systems, it is possible to specify not only the path to the repository,
but also a scope within the repository. Trac will then only show information
related to the files and changesets below that scope. The Subversion backend for
Trac supports this; for other types, check the corresponding plugin's documentation.